Green Synthesis and Multifunctional Characterization of Capparis decidua-Mediated Iron Oxide Nanoparticles for Enhanced Antioxidant and Therapeutic Applications

The growing need of biocompatible nanomaterials that possess therapeutic activity has put the paradigm of green synthesis in the centre-stage of nanotechnological research. This study documents the synthesis of iron oxide nanoparticles (FeNPs) through a phytochemical-mediated synthesis using aqueous leaf extracts of xerophytic shrub Capparis decidua which is a natural source of bioactive polyphenols, alkaloids and flavonoids. Under controlled thermal conditions (60 -70 ℃) the synthesis used ferric chloride hexahydrate as the metallic precursor to give spherical nanoparticles whose hydrodynamic diameter is 88.5nm (DLS) and core size is 48-87nm (SEM). The FTIR-based comprehensive characterization revealed the existence of the phenolic hydroxyl group (3403 cm⁻¹), amide groups (1643, 1541 cm⁻¹) and FeO stretching bands (664 cm⁻¹), which verified the existence of the phytochemical-mediated reduction and stabilization processes. The electrostatic repulsion of zeta potential -28.3mV exhibited strong colloidal stability. Multifunctional antioxidant analysis showed outstanding radical scavenging capacities against the DPPH (IC50: 47.82±1.86 µg/mL) and the ABTS (IC50: 64.31 0.97 1 -1 mL) radicals and nitric oxide radicals (IC50: 68.54±0.79 µg/mL) which was close to the ascorbic acid standards. This combination of sustainable synthesis protocols and strong bioactivities makes the FeNPs one of the promising candidates in therapeutic use in oxidative stress management, nanomedicine and biomedical interventions.